scdaemon: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/scdaemon - from package: gnupg2-smime

You may install the required package with command yum install {package}

Error in other languages:
scdaemon: bevel nie gevind nie
scdaemon: comandă negăsită
scdaemon: comando não encontrado
scdaemon: commande introuvable
scdaemon: command not found
scdaemon: käsku ei ole
scdaemon: không tìm thấy lệnh
scdaemon: komanda nerasta
scdaemon: Kommando nicht gefunden.
scdaemon: kommandot finns inte
scdaemon: komut yok
scdaemon: nie znaleziono polecenia
scdaemon: níor aimsíodh an t-ordú
scdaemon: no se encontró la orden
scdaemon: no s'ha trobat l'ordre
scdaemon: opdracht niet gevonden
scdaemon: parancs nem található
scdaemon: perintah tidak ditemukan
scdaemon: príkaz nenájdený
scdaemon: příkaz nenalezen
scdaemon: команда не найдена
scdaemon: командата не е открита
scdaemon: 命令找不到
scdaemon: コマンドが見つかりません